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path: root/arch/arm64/kernel/cpuinfo.c
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2014-08-01arm64: add newline to I-cache policy stringMark Rutland
Due to a missing newline in the I-cache policy detection log output, it's possible to get some ratehr unfortunate output at boot time: CPU1: Booted secondary processor Detected VIPT I-cache on CPU1CPU2: Booted secondary processor Detected VIPT I-cache on CPU2CPU3: Booted secondary processor Detected VIPT I-cache on CPU3CPU4: Booted secondary processor Detected PIPT I-cache on CPU4CPU5: Booted secondary processor Detected PIPT I-cache on CPU5Brought up 6 CPUs SMP: Total of 6 processors activated. This patch adds the missing newline to the format string, cleaning up the output. Fixes: 59ccc0d41b7a ("arm64: cachetype: report weakest cache policy") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-07-18arm64: add runtime system sanity checksMark Rutland
Unexpected variation in certain system register values across CPUs is an indicator of potential problems with a system. The kernel expects CPUs to be mostly identical in terms of supported features, even in systems with heterogeneous CPUs, with uniform instruction set support being critical for the correct operation of userspace. To help detect issues early where hardware violates the expectations of the kernel, this patch adds simple runtime sanity checks on important ID registers in the bring up path of each CPU. Where CPUs are fundamentally mismatched, set TAINT_CPU_OUT_OF_SPEC. Given that the kernel assumes CPUs are identical feature wise, let's not pretend that we expect such configurations to work. Supporting such configurations would require massive rework, and hopefully they will never exist. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18arm64: cachetype: report weakest cache policyMark Rutland
In big.LITTLE systems, the I-cache policy may differ across CPUs, and thus we must always meet the most stringent maintenance requirements of any I-cache in the system when performing maintenance to ensure correctness. Unfortunately this requirement is not met as we always look at the current CPU's cache type register to determine the maintenance requirements. This patch causes the I-cache policy of all CPUs to be taken into account for icache_is_aliasing and icache_is_aivivt. If any I-cache in the system is aliasing or AIVIVT, the respective function will return true. At boot each CPU may set flags to identify that at least one I-cache in the system is aliasing and/or AIVIVT. The now unused and potentially misleading icache_policy function is removed. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18arm64: cpuinfo: record cpu system register valuesMark Rutland
Several kernel subsystems need to know details about CPU system register values, sometimes for CPUs other than that they are executing on. Rather than hard-coding system register accesses and cross-calls for these cases, this patch adds logic to record various system register values at boot-time. This may be used for feature reporting, firmware bug detection, etc. Separate hooks are added for the boot and hotplug paths to enable one-time intialisation and cold/warm boot value mismatch detection in later patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>